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Fixed an infinite loop in NioClientSocketPipelineSink.register() when Selector fails to open

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This commit is contained in:
Trustin Lee 2008-12-08 23:49:21 +00:00
parent f2807aaf51
commit 878eda0d26
1 changed files with 87 additions and 48 deletions
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135
src/main/java/org/jboss/netty/channel/socket/nio/NioClientSocketPipelineSink.java
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@ -30,6 +30,7 @@ import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.Iterator;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
@ -47,6 +48,7 @@ import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.LinkedTransferQueue;
import org.jboss.netty.util.ThreadRenamingRunnable;
/**
@ -167,55 +169,61 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
private final class Boss implements Runnable {
private final AtomicBoolean started = new AtomicBoolean();
private volatile Selector selector;
private final Object selectorGuard = new Object();
volatile Selector selector;
private boolean started;
private final AtomicBoolean wakenUp = new AtomicBoolean();
private final Object startStopLock = new Object();
private final Queue<Runnable> registerTaskQueue = new LinkedTransferQueue<Runnable>();
Boss() {
super();
}
void register(NioSocketChannel channel) {
// FIXME: Infinite loop on selector creation failure.
// Apply the same fix with what's applied in NioWorker.register()
boolean firstChannel = started.compareAndSet(false, true);
Runnable registerTask = new RegisterTask(this, channel);
Selector selector;
if (firstChannel) {
try {
this.selector = selector = Selector.open();
} catch (IOException e) {
throw new ChannelException(
"Failed to create a selector.", e);
}
} else {
selector = this.selector;
if (selector == null) {
do {
Thread.yield();
selector = this.selector;
} while (selector == null);
synchronized (startStopLock) {
if (!started) {
// Open a selector if this worker didn't start yet.
try {
this.selector = selector = Selector.open();
} catch (Throwable t) {
throw new ChannelException(
"Failed to create a selector.", t);
}
// Start the worker thread with the new Selector.
boolean success = false;
try {
bossExecutor.execute(new ThreadRenamingRunnable(
this, "New I/O client boss #" + id));
success = true;
} finally {
if (!success) {
// Release the Selector if the execution fails.
try {
selector.close();
} catch (Throwable t) {
logger.warn("Failed to close a selector.", t);
}
this.selector = selector = null;
// The method will return to the caller at this point.
}
}
} else {
// Use the existing selector if this worker has been started.
selector = this.selector;
}
assert selector != null && selector.isOpen();
started = true;
registerTaskQueue.offer(registerTask);
}
if (firstChannel) {
try {
channel.socket.register(selector, SelectionKey.OP_CONNECT, channel);
} catch (ClosedChannelException e) {
throw new ChannelException(
"Failed to register a socket to the selector.", e);
}
bossExecutor.execute(new ThreadRenamingRunnable(
this, "New I/O client boss #" + id));
} else {
synchronized (selectorGuard) {
selector.wakeup();
try {
channel.socket.register(selector, SelectionKey.OP_CONNECT, channel);
} catch (ClosedChannelException e) {
throw new ChannelException(
"Failed to register a socket to the selector.", e);
}
}
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
}
@ -223,12 +231,13 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
boolean shutdown = false;
Selector selector = this.selector;
for (;;) {
synchronized (selectorGuard) {
// This empty synchronization block prevents the selector
// from acquiring its lock.
}
wakenUp.set(false);
try {
int selectedKeyCount = selector.select(500);
processRegisterTaskQueue();
if (selectedKeyCount > 0) {
processSelectedKeys(selector.selectedKeys());
}
@ -242,18 +251,17 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
if (shutdown ||
bossExecutor instanceof ExecutorService && ((ExecutorService) bossExecutor).isShutdown()) {
synchronized (selectorGuard) {
if (selector.keys().isEmpty()) {
synchronized (startStopLock) {
if (registerTaskQueue.isEmpty() && selector.keys().isEmpty()) {
started = false;
try {
selector.close();
} catch (IOException e) {
logger.warn(
"Failed to close a selector.",
e);
"Failed to close a selector.", e);
} finally {
this.selector = null;
}
started.set(false);
break;
} else {
shutdown = false;
@ -280,6 +288,17 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
}
}
private void processRegisterTaskQueue() {
for (;;) {
final Runnable task = registerTaskQueue.poll();
if (task == null) {
break;
}
task.run();
}
}
private void processSelectedKeys(Set<SelectionKey> selectedKeys) {
for (Iterator<SelectionKey> i = selectedKeys.iterator(); i.hasNext();) {
SelectionKey k = i.next();
@ -318,4 +337,24 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
NioWorker.close(ch, ch.getSucceededFuture());
}
}
private final class RegisterTask implements Runnable {
private final Boss boss;
private final NioSocketChannel channel;
RegisterTask(Boss boss, NioSocketChannel channel) {
this.boss = boss;
this.channel = channel;
}
public void run() {
try {
channel.socket.register(
boss.selector, SelectionKey.OP_CONNECT, channel);
} catch (ClosedChannelException e) {
throw new ChannelException(
"Failed to register a socket to the selector.", e);
}
}
}
}